Refrigerating apparatus



May 2, l961 c. H. WURTZ ETAL REFRIGERATING APPARATUS Filed Sept. 23, 1958 m 0 2 n s m" m EU! 8 wwu n m .fll g W c f A w 0. r ffl Z M UWL T I Y c B Fig. 2

Unitedstates Patent I 8 2,982,115 REFRIGERATING APPARATUS Filed Sept. 23, 1958, Ser. No. 762,843 3 Claims. (Cl. 62-419) This invention pertains to refrigerating apparatus and especially to two compartment household refrigerators in which frost will not collect and remain in belowor above-freezing compartments.

It has been customary'toplaee the evaporator in the -belowand above-freezing compartments. Such anareither the rangementnot only required frequently defrosting of the evaporator in the above-freezing compartmentbut also "heavy coats of frost formed on the evaporator and all the articles and packages in the below-freezingbompartment. More recently, it was appreciated that if the evaporator were outside of the belowand abovefreezing compartments and air'w'ascirculated from the below-' and above-freezing compartments in heat transferrelation with the evaporator andthence returned to the compartment's, no frost would'collect and remain in either compartment. a V v Y It is an object offthis inventionto provide a simple,'inexpensive household refrigerator requiring only a single freezing.

It is another object of this invention to provide a simple, inexpensive household refrigerator requiring onlya single evaporator in which all frosting anddefrosting takes place on an evaporator located so that the minimum of ductwork will be required.

evaporatorand a minimum of ductwork in which frost will not collect and remain in either the belowor abovefreezing compartment and which will provide rapid ice Patented May 2, 1961 2 orator is provided with an electric heat defrosting means. Defrost water from this evaporator flows onto the false top wall of the above freezin'g compartment and down the rear lwall thereof to tubing carrying it to a place or disposa a Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Figure l is a vertical sectional view of a household refrigerator embodying one form of our invention; and

Figure 2 is a fragmentary vertical sectional view through the drain pan, drain, and liquid trap.

Figure 1 shows a household refrigerator having an upper below-freezing compartment 20 provid'edwith an insulated door 22. Below the below-freezing compartment is an' above-freezing compartment 24 provided with an insulated door 26. Between the two compartments is a horizontal cross fin evaporator 28 which rests upon a drip pan 30 which forms the bottom of the upperportion 'of the cabinet. 'Resting on top of this evaporator 28' is a removable bottom wall 32 which is therefore inlg'ood heat'transfer' relation with the top "of the evaporator 28.

This 'wall32 is suitable for supporting ice trays33- for the quick freezing of ice cubes. The space occupiedby the evaporator 28 between the drip pan 30 and the bottom wall 32 constitutes a first air passage forming a part of the first air circuit which includes the below-freezing compartment 20 having outlet openings 34 adjacent the door 22 which provide communication with a duct 36 extending as a collar around the front portion of the casing 38 over the opening 34.

' The casingi38 surrounds 'the'top and sides of the compartment 20 and joins with the drip pan 30' to provide a substantially sealed compartment. The duct 36 discharges intothe first passage between the drip pan 30 and the bottom wall 32. The air flows from the bottom of the duct 36 through the evaporator 28 which occupies the first passage. At the rear of the compartment 20 is a removable shroud 40 which guides the air into the impeller .It is another object of this invention to provide a sim-- ple,inexpensive household refrigerator in which'the frost formed on the evaporator surfaces when melted during department.

' 1 Itis another'object of this invention to provide a sim- These and other objects are attained in. .the form of household =refrigerator shown in the drawings in which a vertically finned evaporator is located beneath and in"-- contact with the bottom of the below-freezing compartment and hasa .drip pan beneath formin'gthe top of 'a horizontal duct at thetop 'of the above-freezing" compartment. Separate fansare provided for each compartment. A first 'air circuit isprovided-for withdrawing airy-from the below-freezing compartment at the'front thereof and conveying the air'between the;bottom thereof and*the drip pan throughtlie single evaporator toa fan' in the rear wall which returns the air to the belowrfreezing'compartin the rear wail of theabove-freezing compartment-draws "air noa neeomp nmem between this false ywalland "the drippan' and"returns-it throughan opening in the rear wall'to cool the above-freezing compartment {The evap- 42 of a centrifugal fan driven by an electric motor 44.

- The impeller 42 and the motor 44 are removably mounted 45 frosting-will flow into and cool the above-freezing comin an opening in the rear wall of the cabinet46. The opening is sealed by a diaphragm 48 of an elastomeric material clamped by the clamping ring 50 to the flange 52. of the outer rear wall 54 to seal the opening. Between the motor 44 and the impeller 42 is aninsert 56 of foamed plastic. This insert 56 fits into a recess provided in'the discharge shroud 58 surrounding the impeller. '42. This discharge shroud 58 conveys the air expelled by the impeller 42-to the rear air inlets 60 provided in the rear wall 62 of the compartment 20. The casing 38, theduct '36; the 'breaker'strip 37 and theshroud 58 are enclosed ininsulation 63 which is cast or foamed in place. 1

. above andbelow for receiving, the upper and lower portions 64 and-66 of a sheathed electric heater. The drip pan is provided with a drain. pipe outlet 68 at its lowest point which extends downwardlyintoa cup 70 forming a liquid trap. The drain tube 68.is provided with an elecmerit throughopeningsat the upper rear thereof. The "above-freezing compartment has la'false top wallgproviding a horiz'orltal 'duct beneath the drip pan; A second fan tricheater section72 and the cup 70 is provided: with a heater section 74.. A heater section 76 isalso provided beneath the impeller 42 within' the shroud 58. A.-plas'tic.

breaker strip 78 isprovided between the bottom wail-15 32 and the shroud -40. Thexheater sections 72,}74and 76 are electrically connected to be. "energized coincidentally with the heater sections 64. and. during ,a :defrosting period igrhe abov'freezing mpartment enclosedlwithixiia liner 80 having an outlet opening 82 at th f m f' pan 30 there is provided a thin layer of insulation 86, the top surface of which slopes downwardly to the rear. Be- ,tween the insulation 86 and'the drip pan 30 there is provided a second horizontal passageway 88. The front and rear ends of the passageway are provided inthefoam insulation 135 and 137; At the rearof the liner 80 there is provided a shroud 90 for conducting air from the re- ,-turn opening 84 to the opening 92 in the rear 'wall communicating with the interior of the impeller 94 of a centrifugal fan driven by an electric motor 96 which extends through an opening in the rear wall 54. Surrounding the impeller 94 is a discharge shroud 98 which conducts the air discharged from the impeller'tothe opening 121 in the rear wall of the liner 80; The shroud 98 and the liner 80 are enclosed in foam insulation 139. The circulationof air from the above-freezing compartment 24 through the opening 82, the passage 88, the shroud 90, c

the impeller 94, the discharge shroud 98 and the opening :20,- cools the above-freezing compartment 24. ---Frost will not accumulate in either of the compartments. However, frost will accumulate on the evaporator '28. Therefore, periodically, the evaporator is heated by the electric heater sections 64 and 66 and at the same time, the heater sections 72, 74 and 76 are energized to melt the frost which accumulates at thesepoints. The melting frost will flow down through the drain tube and .fill and overflow the cup 70. --fiow down the rearwardly sloping upper surface ofthe insulation 86 and pass through the opening 84 and be carried downwardly by the shroud 90. The shroud 90 is provided with an outlet opening 123 at the bottom which allows the defrost water to flow down the back wall of the liner 80. At the bottom rear of the liner 80 there is provided a discharge tube 125 which extends to some means for disposing of the defrost water. 7 1

The evaporator 28 is supplied with liquid refrigerant This defrost water will from a liquefier which includes a sealed motor compressor defrosting. Defrosting is accomplished rapidly enough that no thawing will take place within the below-freezing compartment 20 and the above-freezing compartment is prevented from rising above desirable refrigerating tem perature for any substantial period.

While the embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows: I 1. A refrigerator having means forming an upper below-freezing compartment and an above-freezing compartment beneath the upper compartment and a first air passageway extending from the front to the rear of said upper "compartment between the bottom of the upper compartment and the top of the compartment beneath havinga front inlet and a rear outlet connecting with-the interior;

of said upper compartment to form a first air circuit, an evaporating means entirely beneath said upper compartment and entirely in said air passageway having air passages, said upper compartment having a bottom wall ex- '-te'nding over and in heat transfer relation with said evap forating means and forming 'a confining wallof said first =airpassageway, a second air passageway out of com munication with said first passageway and first air circuit 1 extending from front to rear across the. top of said above and drain trap for draining defrost water therefrom onto sa1dwall, said wall being provided with means for con.- ducting defrost water. through said second air passageway freezing compartment beneath and in heat transfer l'eifl-g,

:tiomwith said first 'passagewayrhaving' a front inlet and a rear outlet for cooling said above'freezingcompartment, a metal separating wall between and separating said first and second air passagewaysand separating said second air passageway from said evaporating means, and a second fan means for circulating air from said above-freezing compartment through said second passageway out of communication with but in heat transfer relation with said first passageway through said metal separating wall for cooling said above-freezing compartment.

2. A refrigerator having means forming an upper be low-freezing compartment and an above-freezing compartment beneath the upper compartment and a first air passageway extending from the front to the rear of said upper compartment between the bottom of the upper compartment and the top of the compartment beneath having a front inlet and a rear outlet connecting with the interior of said upper compartment to form a first air circuit, an evaporating means in said air passageway having air passages, said upper compartment having a bottom wall extending over and in heat transfer relation with said evaporating means and forming a confining wall of said first air passageway, fan means for circulating air from said upper compartment through said inlet and said firstv air passageway in heat transfer relation. with said evaporator and through said outlet back to said upper compartment, said first air passageway and said first air circuit being out of communication with but in heat transfer relation with said compartment beneath to keep said compartment beneath at refrigerating temperatures, a second airpassageway out of communication. with said ing said above freezing compartment, a metal separating wall between and separating said first and secondair passageways and separating said second air passageway from ;said evaporating means, a secondfan means for circulating air from'said above freezing compartment through said second passageway out of communication with but in heat transfer relation with said first passageway through said metal separating wall for cooling said above freezing compartment, means for defrosting said evaporating means, and means for conveying the defrost water through said second air passageway and thence into heat transfer relation with said above freezing compartment.

3. A refrigerator having means forming an upper below-freezing compartment and an above-freezing com- .partment beneath the upper compartment and a first air passageway between the bottom of the upper compartment and the top of the compartment beneath having an inlet and an outlet connecting with the interior of said upper compartment to form a first air circuit, an evaporating means entirely beneath said upper compartment and entirely in said air passageway and having air passages, said upper compartment having a bottom wall extending over and in heat transfer relation with said evaporating means and forming a confining wall of said first -air passageway, said first air passageway being provided with a :drip'pan beneath said evaporating means, said pan having its lower face exposed, a second air passageway extending from front to rear directly beneath the lower face of said pan, a wall at the top-of said. abovefreezing compartment separating said compartment from said second air passageway, said drip pan separating said second passageway from the evaporator, said wall having 'a front opening communicating with said above-freezing compartment and a rear opening, a shroud connecting *with said rear opening and being located in said above freezing compartment, means for defrosting said evaporating means, said drain pan beingprovided with a drain from said drain to said shroud, a fanassociatedwith said i.

shroud for circulating airfrorn said above-freezing coms: 1,. LI!

6 partment through said second air passageway in contact References Cited in the file of this patent with the lower face of said pan and in heat transfer with UNITED STATES PATENTS said defrost water and back to said above-freezing compartment, said shroudhav-ing a drain for draining the 2,617,268 Ashby 1952 defrost water therefrom. 5 2,866,323 Candor Dec. 30, 1958 

